In the previous invention entitled “Thiation of Carbon Nanotubes and Composite Formation” (U.S. Pat. No. 7,713,508 B2), graft polymerization initiated on dithioester-functionalized carbon nanotubes and their composite formation was first described by Curran, et al. Dithiocarboxylic ester formation catalyzed by phosphorus pentasulfide was well documented for various alcohols and carboxylic acid. The role of phosphorus pentasulfide was proposed to be activation of carboxylic functional group for nucleophilic attack and thiation of hydroxyl and carbonyl functional groups. Utilizing dithioester as a chain transfer agent for living free-radical polymerization of monomers, preferably through the mechanism of Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization, multi-walled carbon nanotube-polystyrene (MWCNT-PS) was synthesized and their composite formation with polystyrene was well characterized (J. Mater. Res. 2006 21, 1071-1077). Thin films made from the composite with low MWCNT loadings (less than 0.9 wt. %) were optically transparent and no evidence of aggregation of nanotubes in the thin film or solution was observed. The result from the conductivity measurement as a function of MWCNT loadings suggests two charge transport mechanisms: charge hopping in low MWCNT loadings (0.02-0.6 wt. %) and ballistic quantum conduction in high loadings (0.6-0.9 wt. %). The composite exhibits dramatically enhanced conductivity up to 33 S/m at a low MWCNT loading (0.9 wt. %).
An improved method was developed to connect general graphitic structures to other organic based monomers. The present invention comprises organic hybrid nanomaterials with graphitic structures covalently bonded via chemically reactive groups on the outer walls of the structure and methods for forming the covalently bonded structures to many other organic based monomers and/or polymers through RAFT polymerization utilizing dithioester as a chain transfer agent. The present invention also comprises nanocomposite formation of such organic hybrid nanomaterials with plastic to form graphitic nanocomposite reinforced plastic articles.